The first one I am pretty certain (the one in your avatar) is what was previously known as Lobivia ferox var. longispina, the genus Lobivia has now been merged with Echinopsis. So most likely Echinopsois ferox etc. etc. Though there is a rule in nomenclature that if a species name is already in use and another genus merges and has the same species the species that had the name first within the merged genus, then the later addition loses it's species names and gets a new one. Make sense?

Here's a good example: When the genus Trichocereus was merged into Echinopsis a problem arose. There was already an Echinopsis bridgesii and they had to come up with a name because Trichocereus bridgesii had to become something different. So what they did was keep Echinopsis bridgesii as it always was and they renamed Trichocereus bridgesii to Echinopsis lageniformis. Very confusing, and many people still just call it T. bridgesii, including myself. Though it can be helpful to know the true name and the synonym for identification purposes because there are many schools of thought on what should be called what and what truly is species X etc. Cactus nomenclature is totally insane, it doesn't help when so many of the genera and species are extremely variable and some particularly difficult to ID.